Piping bag



FIG. 1 is a perspective view of a piping bag embodying my design, showing the piping bag expanded and in a closed use configuration with environment;

FIG. 2 is a rear perspective view of the piping bag of FIG. 1, shown partly open;

FIG. 3 is a front elevation view thereof shown flat, the rear elevation being a mirror image thereto;

FIG. 4 is a right side elevation thereof, the left side elevation being a mirror image thereto; and,

FIG. 5 is a top view thereof.

The broken lines shown in FIG. 1 depict environmental subject matter that forms no part of the claimed design. 

CLAIM The ornamental design for a piping bag, as shown and described. 